Over-the-wire ultrasound system with torque-cable driven rotary transducer

Abstract

Disclosed are embodiments of devices and methods for imaging the inside of a body part, such as a blood vessel. In particular embodiments, a catheter has a chamber within which is a transducer. A wire guide channel extends throughout the length of the catheter. The transducer is rotatable about the wire guide channel and the transducer is driven by a cable or other device that is connected to a motor which is located outside the catheter. In one form, a torque cable connects the transducer to the motor. In other embodiments, a pusher piece having a plurality of lumens is positioned in the catheter. Each of the lumens is sized to receive a cable, wire, and/or flushing fluid. The lumens maintain the orientation and separation of the cables, wires, and/or to flushing fluid.

The invention claimed is: 
     
       1. A medical ultrasound device comprising:
 a catheter having an internal chamber and a longitudinal axis extending through the internal chamber; 
 a drive shaft extending substantially along the longitudinal axis; 
 a non-rotating wire guide positioned along the longitudinal axis within the internal chamber; 
 a transducer configured for transmitting and/or receiving ultrasound signals and operatively coupled with the drive shaft, the transducer and the drive shaft positioned within the internal chamber, wherein the transducer is rotatable about the longitudinal axis and the wire guide in response to rotation of the drive shaft; 
 a torque cable positioned within the internal chamber, the torque cable offset a distance from the longitudinal axis, the torque cable operably connected to the drive shaft and a motor so that the drive shaft rotates in response to the torque cable; 
 a first gear positioned within the internal chamber, said first gear operably connected to the torque cable; 
 a second gear positioned within the internal chamber, said second gear operably connected to the drive shaft, wherein the second gear is configured to interact with the first gear such that the second gear is configured to rotate when the first gear rotates; 
 a pusher piece positioned within the internal chamber and extending from an application end to a control end, the pusher piece defining a plurality of lumens that span a length of the pusher piece wherein one of the plurality of lumens is sized to receive the wire guide and another of the plurality of lumens is sized to receive the torque cable; and 
 a stationary mount positioned within the internal chamber distal to the pusher piece, wherein the first gear is rotatably mounted to the stationary mount piece, and the second gear is rotatably mounted to the stationary mount piece. 
 
     
     
       2. The device of  claim 1 , wherein the first gear has a rotational axis offset from the longitudinal axis and the first gear is configured to rotate about the rotational axis; and
 the second gear is configured to rotate about the longitudinal axis when the first gear rotates. 
 
     
     
       3. The device of  claim 1 , further comprising:
 a mounting piece positioned within the internal chamber, the mounting piece is configured to receive the transducer and the drive shaft, wherein the mounting piece defines a lumen that aligns with the longitudinal axis and is sized to receive the wire guide such that the wire guide is non-rotatable, and the mounting piece is configured to rotate about the longitudinal axis. 
 
     
     
       4. The device of  claim 3 , further comprising:
 a slip ring assembly operably connected to the mounting piece and the torque cable. 
 
     
     
       5. The device of  claim 4 , wherein the mounting piece defines a bore that extends along the longitudinal axis, and the slip ring assembly includes said stationary mount piece configured to retain the drive shaft sized to operatively mate with the bore. 
     
     
       6. The device of  claim 1 , wherein another of the plurality of lumens of the pusher piece is sized to receive one or more transducer electrical wires operably connected to the transducer. 
     
     
       7. A medical ultrasound device comprising:
 an elongate housing having a longitudinal axis; 
 a transducer positioned within the elongate housing, the transducer configured for transmitting and/or receiving ultrasound signals; 
 a torque cable extending within the elongate housing, the torque cable set to one side of the longitudinal axis; 
 a mounting piece positioned within the elongate housing and operatively coupled with the torque cable, the mounting piece also configured to receive the transducer, wherein the mounting piece defines a lumen that aligns with the longitudinal axis; 
 wherein the torque cable is operably connected to the mounting piece to transmit torque to the mounting piece and is configured to rotate the mounting piece about the longitudinal axis; 
 a gear assembly positioned within the elongate housing, the gear assembly having a first gear interactively coupled to a second gear, wherein the first gear is rotatably mounted to a stationary mount piece within the elongate housing and the first gear is operatively connected to the torque cable, and wherein the first gear is rotatably mounted to the stationary mount piece, and the second gear is rotatably mounted to the stationary mount piece about the longitudinal axis; 
 a pusher piece positioned within the elongate housing and extending from an application end to a control end, the pusher piece defining a plurality of lumens that span a length of the pusher piece wherein one of the plurality of lumens is sized to receive the torque cable. 
 
     
     
       8. The device of  claim 7 , further comprising:
 a non-rotating wire guide positioned within the housing along the longitudinal axis. 
 
     
     
       9. The device of  claim 8 
 wherein one of the plurality of lumens is sized to receive the wire guide. 
 
     
     
       10. The device of  claim 8 , wherein the lumen is sized to receive the wire guide and includes an ultrasound-transmissive fluid. 
     
     
       11. The device of  claim 8 , further comprising:
 a motor positioned exteriorly to the elongate housing; and 
 a gear assembly mounted on the motor, wherein the torque cable is operably connected to the gear assembly, the torque cable further configured to receive the wire guide therein. 
 
     
     
       12. The device of  claim 7 , further comprising:
 a motor positioned exteriorly to the elongate housing, wherein the motor is operably connected to the torque cable. 
 
     
     
       13. The device of  claim 7 , wherein the torque cable is offset a distance from the longitudinal axis. 
     
     
       14. The device of  claim 7 , wherein the transducer is operatively coupled with a drive shaft extending substantially along the longitudinal axis, the transducer and the drive shaft positioned within the elongate housing, wherein the transducer rotates about the longitudinal axis in response to rotation of the drive shaft.